I want to echo what David said here about the Dobzhansky quote. It's
not that particulars don't make sense without the light of evolution.
Obviously, you can think about blood circulation, biomechanics,
metabolic pathways, RNA transcription, protein synthesis, etc.
without thinking much about evolution.

What Dobzhansky meant when he said "makes sense" has to do with the
big picture. Why things are the way they are rather than isolated
"brute facts"? That's the sort of questions that evolution answers.
Why are ducks more like chickens than monkeys? You don't need
evolution to note the similarity or even to do research that takes
advantage of knowledge of the similarity, but if you want the
similarity to "make sense" rather then to be a "that's just the way
it is" evolution is your answer.

Same for a host of historical and biogeographical questions. Same for
why similarities but why differences. For example, biochemical,
genetic code, etc. unities, but also, the diversities. Evolutionary
ideas give explanation to these things that go "beyond" that's the
way it is or that's the way God made it. Why is argon different from
gold? Atomic theory in its various dimensions allow us to "make
sense" of the differences. You can do a lot of research on argon and
gold without asking the question why are these substances the way
they are and whether there is any unifying theory that explains that.
Same idea in biology.

TG

On Sep 14, 2005, at 10:29 AM, David C Campbell wrote:

>
> Everything in biology only makes sense in the light of evolution is
> true only in the sense of "everything at once". You can turn on a
> light switch without having a clue about electricity, but if you
> want a
> full understanding of what's happening, you need knowledge of basic
> physics. Likewise, I can count animals without worrying how they got
> that way, but if I want to make sense of the numbers, I must have some
> idea about the factors that influence animal populations, and these
> tie
> directly into evolution. Again, medical testing can be done on an ad
> hoc basis of "this works OK", but evolution provides a number of basic
> explanations, such as (a) due to their common ancestry, organisms have
> basic biochemical and physiological similarities, with greater
> similarity closely reflecting the degree of relatedness. Thus,
> testing
> medical procedures on animals, especially primates, is expected to
> be a
> good proxy for humans. (b) features of humans reflect their
> evolutionary heritage as well as their current environment, so some
> adaptations for past conditions may be problematic now (e.g., ability
> to consume a lot of food in case of irregular availability becomes a
> problem in times of ready availability; sturdy teeth for raw food
> gives
> orthodontists opportunities now that our skeletons as a whole are
> becoming less massive, including the jaws; our backs have only a few
> million years of mainly upright use and are not as strong as we think
> when trying to lift heavy stuff) (c) disease organisms are in a tight
> competition to defeat the body's defenses enough to survive and
> reproduce without doing so much harm as to kill the host before the
> disease can be transmitted. Thus, pathogens are likely to respond
> rapidly to challenges (new antibiotics, etc.), and the really deadly
> stuff will be things that normally infest other organisms and
> accidentally get into us (bird flu, ebola, larval tapeworms, etc.)
> (d)
> Cancer, to survive, must constantly evolve ways to evade the body's
> controls and defenses. (e) People are strongly inclined to act in
> their own selfish interests and have a drive to reproduce.
> Expectations of human behavior and likely means of disease
> transmission
> that do not take these into account will probably be wrong. (f) other
> things I haven't thought of off the top of my head.
>
> Evolution is a uniting theory for all of biology, allowing us to
> connect every aspect of it into a coherent framework. While
> working on
> the details, it's not always necessary and may even be distracting to
> focus on it, just as in the example of using Newtonian physics rather
> than a more accurate and fundamental but more complicated relativistic
> calculation in dealing with spacecraft launches.
>
> ----------------------------------------
> Dr. David Campbell
> 425 Scientific Collections
> University of Alabama, Box 870345
> Tuscaloosa AL 35487
> "James gave the huffle of a snail in
> danger But no one heard him at all" A.
> A. Milne
>